Knowledge and skills.

If you read me often, you realize that I generally advise people to prepare. Plan for things that can happen, and stock accordingly. Stock material supplies, AND stock knowledge. Knowledge is worth it's weight in gold for it's own sake.

What does your library look like? Mine has a LOT of "How TO" books, and I have a lot of personal knowledge. I have the knowledge in my head and the books for reference.

I can blacksmith, I can garden (quite well too, I might add). I am a decent jackleg primitive paramedic. I can fabricate in wood, steel, aluminum and brass. I can smelt copper, cast and forge...iron or brass. I can make bows. I can live off the land with just a knife and enough clothing to keep me from dying of exposure (I was actually comfortable for about 2 weeks that way one summer, just to see if I could....). I can make fire about any way possible. I can fell a tree and move the logs...Then spit and stack them as building material or as firewood...all by hand. I can clean your wound and then stitch you up and dress it and care for it to keep it from being infected.

I can, given a bit of time (and suitable material), produce adobe, clay bricks, tan leather, preserve food...and make containers to protect it.  Given flint, I can make all sorts of useful things. I can make black powder given the materials...and I can find or make those, given time. I can identify and locate and use most herbs available in the midwestern United States (my AO).

I learned to do these things for fun...and I occasionally do them outside of a classroom...for real (except the wounds).

I can engineer and build structures, including bridges and such. I can do basic (and not so basic) plumbing. I can work with nearly any home or light industrial wiring. I can make and use simple machines in innovative ways...Levers, pulleys, inclined planes, rollers, etc (and I occasionally still do, even when there is power equipment that can do it easier...Just for practice).

I can repair almost anything, except bad bearings and vehicle electronics (and I can likely cobble up or substitute temporary replacements for those in a pinch).

As importantly, I have close friends who are dependable who can do the same. The pool of knowledge available is deep and broad. I was lucky. I had a great set of teachers to start me out in my father and his father. I took it from there. And I have good people around me who can do the same.

I need more chemistry and medical knowledge...but I am working on that.

How about you? If you need help moving a washing machine, sharpening that knife, or changing your oil, you are a risk rather than an asset if and when. If you can't fix anything in your house, can't change the brakes on your car, can't build a wall or roof a home, glaze a window, swing an axe, change your own sparkplugs, fell a tree,  pull a splinter or dress the wound, or things like that, then you need to learn, or at least have that knowledge on your bookshelf.

Otherwise, you are a liability. Or will be.